The Time-space Evolution And Influencing Factors Of Ecological Security In Gansu Province

Gansu Province is the important part of China's ecological security strategic pattern and the important strategic channel for China and the hub for western construction.Therefore,carrying out ecological security research in Gansu Province is conducive to the construction of ecological civilization in Gansu Province,to the protection of national ecological security,and to the promotion of national unity,prosperity and development in the northwest region and stability of the frontier.This paper takes 12 prefecture-level cities and 2 autonomous prefectures in Gansu Province as the research area,takes ecological security as the research object,and takes 2008-2016 as the research time period.Through the comprehensive evaluation method,the ecological security situation of Gansu Province in 2008-2016 was evaluated;the Markov matrix,the spatial Markov matrix and the space panel model were used to further analyze the changes of ecological security under the conditions of time lag,space lag and space-time lag.Finally,the main influencing factors of ecological security in Gansu Province were analyzed by Grey correlation method.The main conclusions are as follows:(1)In addition to Lanzhou,the ecological safety assessment values of Gansu Province in2008-2016 were not high and the change range was small.The ecological safety level of the whole province showed the characteristics of Spindle structure.However,the overall shows a trend of growth.The ecological security level also transitions from critical security to general security and safety,indicating that the ecological environment in Gansu Province has generally improved.Among them,the ecological security evaluation value of Jiayuguan,some central areas of Gansu and Gannan area increased the most,and the growth rate in most areas of Hexi was small,while the evaluation values in Jiayuguan and Longnan area showed a downward trend.(2)From the time evolution characteristics of ecological security level: From 2008 to2016,the changes from critical safety level to safety level in Gansu Province are relatively stable,and the higher the level,the stronger the stability;the ecological security of various regions in Gansu Province is tend to better;the probability of transition between adjacent levels is greater,and the change of security status is not large;the ecological security evolves frequently in the intermediate level.From the spatial evolution characteristics of ecological security level: There is a correlation between ecological security in various regions,spatial effects are significant,and ecologicalsecurity shows a certain degree of "convergence" in space,but this spatial effect does not follow a certain proportion changes;spatially,the ecological security level of the central and northern regions of the Hexi,the southwestern region,and the some areas in middle of Gansu has been improved,while the Jiayuguan ecological security level has declined.From the characteristics of time-space evolution of ecological security: Under the time lag condition,the ecological value of the previous year has a significant positive impact on the ecological value of the area;under the condition of spatial lag,the ecological value of the neighboring area in the same period also has a positive impact on the ecological value of the area;under the time-space lag condition,the ecological status of the neighborhood of past year has no significant effect on the ecological value of the area.(3)The influencing factors of ecological security in Gansu Province and various regions have the following characteristics:the degree of relevance of each index varies from 2008 to2016,and the degree of influence from large to small is the response layer,the state layer and the pressure layer;From the analysis of each regions,the degree of relevance is the response layer>the state layer>the pressure layer in the Central,Eastern and Southwest Gansu;the degree of relevance of Hexi area is pressure layer>state layer>response layer;and the degree of relevance of southern Gansu is state layer>response layer>pressure layer.